1. Field of the Invention
This invention relates to a power supply for a laser diode, the power supply and laser diode being housed in a common module. The laser diode is intended for use in optical fibre communication.
2. Background Art
One known application for a laser diode is for transmission of digital information at some 10.sup.8 megabits per second along an optical fibre as part of a local area network. The diode is formed in a metal housing together with an integral photodiode to monitor the laser's rear-facet emission. The housing is positioned at an optical part of a module, which is connected on a printed circuit board which contains electronics for power supply and signal modulation of the laser. To stabilise the power supply to provide a constant mean power output the photodiode is coupled to a circuit comprising a multiplicity of operational amplifiers which regulate the current supply to the laser diode. Alternatively, a semi-custom chip has been employed. However, both circuit types are relatively, expensive and too bulky to include within the module itself.